So long as all parts have been reconnected the way they were, and so long as the battery isn't faulty, it should work. However, it is possible that they is just no charge in the battery itself. If you're sure that everything has been reconnected properly try plugging it in to charge for a while - even if it doesn't indicate that it's charging (and may be so low in power that it does not turn on the screen yet). Just be careful with it though. Don't put anything flammable around it, keep an eye on it and if it heats up disconnect it immediately.